An interesting fact is that the USB ports (actually an RJ45 connector) on APC UPSes not only speak USB, but also serial apcsmart and dumb voltage-signalling as well! This is something that one of our users discovered by accident. With the Custom RJ45 cable (actually a RJ45 to serial cable) described below plugged into the APC UPS USB socket at one end and the other end plugged into a serial port on your PC, any APC USB UPS (except some of the newer really low cost models) will act as a serial-line device.